1. Field
The following description relates to an aperture-coupled microstrip antenna and a manufacturing method thereof.
2. Description of Related Art
In the medical field, a wireless body area network has been implanted in a human body, or attached on a surface of the human body, to collect medical data of a patient. Conditions of the patient may be continuously monitored and inspected through such a communication system, so that an emergency situation is handled. In this regard, an antenna has been used to establish a wireless link between a wireless medical device present in or on a human body and an external device present out of the human body, and to efficiently inspect human body information.
However, a wearable antenna worn on a human body is easily affected by conditions of the human body, including a high dielectric constant (high-k) and a high conductivity. Therefore, performance of the wearable antenna may be reduced when compared to an antenna in a free space. That is, a non-directional radiation pattern of the wearable antenna causes a concentration of radiated power toward the human body, thereby reducing a radiation efficiency of the wearable antenna. In addition, since the human body including the high-k and the high conductivity absorbs the radiated power, an electrical characteristic of the human body generates a mutual impedance causing poor impedance matching with the wearable antenna. Thus, when a conventional antenna technology is applied to a small wearable antenna, a radiation efficiency of the wearable antenna is no more than about 10%. Accordingly, there is a need for an antenna achieving a high radiation efficiency and a small size for application to a human body.